WASHINGTON UNIVERSITY CENTER FOR CELLULAR IMAGING (WUCCI) SHARED RESOURCE: PROJECT SUMMARY Elucidating the mechanisms involved in the development and progression of cancer requires a deep understanding of how changes in tissue / cellular structure relate to loss of function. Imaging technologies have evolved rapidly over the last decade, generating vast improvements in resolution, sensitivity, and speed, and creating fundamentally new opportunities for studying biological processes across many orders of magnitude in real-time in living cells and organisms. The Washington University Center for Cellular Imaging (WUCCI) provides (i) reliable and affordable access to cutting-edge light and electron microscopy instrumentation, (ii) expert guidance in imaging assay design, specimen preparation, image acquisition and analysis, (iii) educational opportunities in the form of hands-on trainings, lunch and learn lectures, workshops and a monthly journal club and (iv) novel imaging and analysis methodologies. As a new Cancer Center Support Grant (CCSG) shared resource (SR), WUCCI will provide an integrated approach to investigate the structure and dynamic behavior of cells and tissues in cancer-related studies. By leveraging a significant institutional investment, SCC researchers gain instant access to a wide variety of advanced cellular microscopy tools which will serve to accelerate the pace, expand the scope, and improve the efficiency of their research. WUCCI services meet the unique requirements of numerous investigators over a wide range of basic and translational research, as well as attract new investigators into the cancer research arena. Importantly, users benefit from the in-depth technical expertise of the Director (James Fitzpatrick) and technical staff with regard to experimental design and interpretation of data. Over the past three years, WUCCI has worked with multiple SCC researchers to implement new imaging assays. These have included the application of two-photon intravital microscopy to longitudinally track disseminated tumor cells in a mouse model of dormancy (Sheila Stewart [MCBP]), the development of x-ray contrast agents to delineate metastatic tumor boundaries in murine long bones (Katherine Weilbeacher [BCRP]), and the application of focused ion beam-scanning electron microscopy (FIB-SEM) serial block face imaging to acquire three-dimensional volumes of mouse gastric tissue at the nanoscale (Jason Mills [MCBP]). In 2018, WUCCI served 235 research laboratories, 75 of which were SCC investigators whose usage represented ~20% of the overall SR consumption. Future plans for the next project period include the acquisition of a light-sheet fluorescence microscope recently funded by the NIH S10 program for the high-speed volumetric imaging of living organoids and cleared tissues, as well as the implementation of the Visiopharm Oncotopix? IHC and ISH image analysis platform. We anticipate that requests for WUCCI services will continue to grow given the need for advanced microscopic imaging and analysis in the study of cancer. Thus, WUCCI, as a new CCSG shared resource, will provide essential services to SCC investigators throughout the next project period.